Under the Guidance of
Submitted by
Project Title
High Intensity Discharge lamps (HID) used for urban street light
are based on principle of gas discharge, thus the intensity is not
controllable by any voltage reduction method as the discharge path
is broken.
White Light Emitting Diode (LED) can replace the HID lamps
where intensity control is possible by pulse width modulation. The
intensity control helps in saving energy during late nights while
traffic density on the streets is low.
A programmable microcontroller is engaged to provide different
intensities at the different times of late night for energy saving for
solar based system, using a charge controller for battery charging,
overload and deep discharge protection
ABSTRACT
PROJECT BLOCK DIAGRAM
HARDWARE REQUIREMENTS
POWER SUPPLY BLOCK
STM 32 DEV. BOARD
SOLAR PANNEL
LED
PWM
MOSFET
PHOTOVOLTAIC CELLS/SOLAR CELLS
LM324
1N4007/1N4148
RESISTOR
CAPACITOR
230 V AC 50 Hz
5V DC
12V step down transformer
Filter(470µf)
5v RegulatorBridge rectifier
Please refer stm32doc provided
MOSFET(IRF 510)
The metal–oxide–semiconductor field-effect
transistor (MOSFET, MOS-FET, or MOS
FET) is a device used for amplifying or
switching electronic signals
The basic principle of the device a voltage on
the oxide-insulated gate electrode can induce a
conducting channel between the two other
contacts called source and drain
It is by far the most common transistor in
both digital and analog circuits, though the
bipolar junction transistor was at one time
much more common.
OPAMP LM324Features
Internally frequency compensated for unity gain
Large DC voltage gain 100 dB
Wideband with 1Mhz (Temperature compensated)
Wide power supply range:
Single supply 3V to 32V
or dual supplies ±1.5V to ±16V
Very low supply current drain (700 μA) essentially
independent of supply voltage
Low input biasing current 45 nA (temperature
compensated)
Low input offset voltage 2mV and offset current:5
nA
Large output voltage swing 0V to V+ − 1.5V
BC547 (NPN –Transistor)
The BC547 transistor is an NPN Epitaxial
Silicon Transistor.
It is used in general-purpose switching and
amplification BC847/BC547 series 45 V, 100
mA NPN general-purpose transistors.
The ratio of two currents (Ic/Ib) is called the DC Current Gain of
the device and is given the symbol of hfe or nowadays Beta, (β).
The current gain from the emitter to the collector
terminal, Ic/Ie, is called Alpha, (α), and is a function of the
transistor itself
1N4148
The 1N4148 is a standard small signal silicon
diode used in signal processing.
The 1N4148 is generally available in a DO-35
glass package and is very useful at high frequencies
with a reverse recovery time of no more than 4ns.
This permits rectification and detection of
radio frequency signals very effectively, as long as
their amplitude is above the forward conduction
threshold of silicon (around 0.7V) or the diode is
biased.
PHOTOVOLTAIC CELLS
Photovoltaic (PV) cells are made of special materials called
semiconductors such as silicon, which is currently the most commonly
used.
Basically, when light strikes the cell, a certain portion of it is
absorbed within the semiconductor material.
PV cells also all have one or more electric fields that act to force
electrons freed by light absorption to flow in a certain direction.
This flow of electrons is a current, and by placing metal contacts on
the top and bottom of the PV cell, we can draw that current off to use
externally.
SOLAR PANEL
Expose the cell to light, and the energy
from each photon (light particle) hitting
the silicon, will liberate an electron and a
corresponding hole.
If this happens within range of the
electric field’s influence, the electrons will
be sent to the N side and the holes to the P
one, resulting in yet further disruption of
electrical neutrality
This flow of electrons is a current; the
electrical field in the cell causes a voltage
and the product of these two is power
The term duty cycle describes the proportion of on time to the regular
interval or period of time; a low duty cycle corresponds to low power,
because the power is off for most of the time.
Duty cycle is expressed in percent, 100% being fully on.
The main advantage of PWM is that power loss in the switching devices
is very low. When a switch is off there is practically no current, and when
it is on, there is almost no voltage drop across the switch.
PWM works also well with digital controls, which, because of their on/off
nature, can easily set the needed duty cycle.
The longer the switch is on compared to the off periods, the higher the
power supplied to the load is.
WORKING OF PROJECT
Solar panel being a current source is used to change battery B1 via D10. While
the battery is fully charged the voltage at cathode point of D10 goes up. This
results in the set point voltage at pin 3 of U1:A to go up above the reference
voltage because the potential divider formed out of R12, 5K variable
resistor,R13 goes up.
This results in pin no 1 of U1:A to go high to switch ‘ON’ the transistor Q1
that places drive voltage to the Mosfet IRF640 .such that the current from solar
panel is bypassed via D11 and the Mosfet drain and source
Simultaneously pin 7 of U1:B also goes high to drive a led D1 indicating
battery is being fully charged
Whenever the solar charge is low the circuit utilizes the power from battery, if
the battery goes into deep discharge ,then it utilizes power from solar power then
the Led’s flashes light
Keil an ARM Company makes C compilers, macro assemblers,
real-time kernels, debuggers, simulators, integrated
environments, evaluation boards, and emulators for
ARM7/ARM9/Cortex-M3, XC16x/C16x/ST10, 251, and 8051
MCU families.
Compilers are programs used to convert a High Level
Language to object code. Desktop compilers produce an
output object code for the underlying microprocessor, but
not for other microprocessors.
i.e the programs written in one of the HLL like ‘C’ will compile the
code to run on the system for a particular processor like x86
(underlying microprocessor in the computer).
For example compilers for Dos platform is different from the
Compilers for Unix platform So if one wants to define a compiler
then compiler is a program that translates source code into object
code.
www.atmel.com
www.beyondlogic.org
www.wikipedia.org
www.howstuffworks.com
www.alldatasheets.com
THANKYOU